Estimating Sheet

# How to determine the required quantity of water to extinguish fire in a building

Construction Software This construction video tutorial is created on the topic of fire demand or required quantity of water for extinguishing the fire that is developed in a building.

The amount of water is described in gpm (L/min) at 20 psi pressure for the time period 2 to 4 hrs. The lowest necessary flow of fire for any single building is 500 gpm for 2 hours and highest necessary flow of fire is 12000 gpm for 4 hours.

The following formula is used to find the flow of fire :-

NFFi = (Ci) x (Oi) x [X + P]I
NFFi denotes Required fire flow

Ci denotes construction factor that is determined with the following formula
Ci = 220 F√A

A denotes the actual floor area equivalent to the biggest floor area including 50% of all other floors.

F denotes construction co-efficient

[X + P]i stands for sum of the exposure factor and the communication factors. It value varies from 1.0 to 1.75 and contains an average value of 1.4.

Oi denotes occupancy factor (0.75 to 1.25)

Based on the above figures, the calculation is made. Go through the following construction video to get more details. 